Visualization of Photo-carrier Diffusion in Monolayer Transition Metal Dichalcogenides

ORAL

Abstract

Understanding of the spatial and temporal evolution of photo-generated charge carriers in atomically thin transition metal dichalcogenides (TMDs) is of critical importance for their application in optoelectronic devices. Using a light-assisted microwave impedance microscope (MIM), we demonstrate the first quantitative mapping of photo-carrier diffusion on monolayer TMDs. When the sample is illuminated by above-gap laser, the circular profile of local photoconductivity measured by the MIM is clearly broader than that of the laser spot. Numerical simulation shows that the free-carrier diffusion length of is on the order of micrometers, corresponding to a carrier lifetime of tens to hundreds of nanoseconds. Our work provides important insights to the remarkable electrical and optical properties of TMDs.

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Presenters

  • Zhaodong Chu

    • Department of Physics, The University of Texas at Austin

Authors

  • Zhaodong Chu

    • Department of Physics, The University of Texas at Austin

  • Jiamin Quan

    • University of Texas at Austin
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA

  • Chun Yuan Wang

    • Department of Physics, The University of Texas at Austin, Austin, Texas, 78712, USA.
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA

  • David Wannlund

    • Department of Physics, The University of Texas at Austin

  • Ali Han

    • Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Kevin Herrera

    • Department of Physics, The University of Texas at Austin

  • Di Wu

    • Department of Physics, The University of Texas at Austin

  • Lain-Jong Li

    • Physical Sciences and Engineering, King Abdullah University of Science and Technology
    • Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Chih-Kang Shih

    • Department of Physics, The University of Texas at Austin, Austin, Texas, 78712, USA.
    • University of Texas at Austin
    • Physics, University of Texas at Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA

  • Xiaoqin (Elaine) Li

    • University of Texas at Austin
    • University of Texas-Austin
    • The University of Texas at Austin
    • Department of Physics and Center for Complex Quantum Systems, Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin, TX 78712, United States
    • Univ of Texas, Austin
    • Department of Physics, The University of Texas at Austin
    • Department of Physics, The University of Texas at Austin, USA

  • Keji Lai

    • University of Texas at Austin
    • Department of Physics, The University of Texas at Austin